zd30 top dead centre

[neville56]

Hi guys i am hoping somebody can help me i have bought a rebuilt zd30 engine and am trying to put it all together, i am having trouble with the timing the timing gears are locked with a bolt and i have put the injector pump in and fitted the chain, removed the bolt and wound it over by hand now here is my problem the marks i used don't line up again. i don't want to do any damage so i have reinstalled the bolt in the timing gears before i attempt any other changes how do i find out if the motor is at top dead centre, and also how can i tell if the injector pump is aligned for number 1 cylinder? Hope somebody can shed some light on my query thanks in anticipation neville56

 

[tweak'e]

i would have to dig out the info but afaik you have to wind over the engine a huge amount of times before the marks line up again.

 

[jonney]

if you turned the engine over by hand it shouldn,t have rotated very much so how about you go backwards again and see if the timing marks re align, remove the timing cog bolt first. i had the same issue with an old subaru where i fitted the new t/ belt and then wound the engine over by hand only to find the next rotation at the hamonic balancer and cam timing marks were way out, so i just reversed the rotation to where it was originally and all was spot on again. not sure on your model but does the timing chain have a painted colour on a link that you align up with the fuel pump cog ?

 

[Rumpig]

I think you need to turn it 2 revolutions before the marks realign, triple check everything or it gets expensive.

 

[tweak'e]

i thought it was something like 90.
you say 2.
google shows we should add those to make 290 revolutions before they line up again.

i think its because they use marks on the chains rather than marks on the head/block to align to. a couple of revolutions doesn't move the chain (and the marks) very far.

 

[jonney]

i thought it was something like 90.
you say 2.
google shows we should add those to make 290 revolutions before they line up again.

i think its because they use marks on the chains rather than marks on the head/block to align to. a couple of revolutions doesn't move the chain (and the marks) very far.

i am sure if the engine was turned over by hand it qwould not be anywhere near 90 turns or revolutions. if you remember which wasy you turned the engine over , just go back the opposite direction until you see the marks re align.